The aim of this proposal is to determine the covalent structure of the propeptides of Type I and Type II procollagen. The carboxyl propeptides of Type I procollagen will be isolated and the complete structure of these peptides determined. Also, the N-terminal propeptide of the pro alpha 2 chain will be analyzed. In the case of Type II procollagen, the studies will focus on the structure of selected regions of the N-terminal and C-terminal propeptides. Special attention will be given to the cleavage sites at which procollagen proteases cleave the molecule, to regions containing interchain disulfide bonds, and to regions which contain carbohydrate. The determination of primary structure will include both protein and DNA sequencing.